Spark-plug for internal-combustion engines and the like.



I E. I. DODDS.

SPARK PLUG FO R INTERNAL COMBUSTION ENGINES AND THE LIKE.

APPLICATION FILED DEC. 1.4. 1915.

Patented Oct. 30, 1917.

STATES PATENT onnion.

ETHAN I. norms, or PITTSBURGH, PENNSYLVANIA, ASSIGNOR To FLANNEBY .BoLTCOMPANY, or PITTSBURGH, PENNSYLVANIA.

SPARK-PLUG FOR INTERNAL-COMBUSTION ENGINES AND THE LIKE.

Specification of Letters Patent.

ApplieationfiledDecember 14. 1915. Serial No. 66,798.

To all whom it may concern:

Be it known that I, ETHAN I. Donns, a citizen of the United States, anda resident of Pittsburgh, in the county of Allegheny and State ofPennsylvania, have invented certain new and useful Improvements inSpark-Plugs for Internal-Combustion Enines and the like; and I do herebydeclare t e following to be a full, clear, and exact description of theinvention, such as will enable others skilled in the art to which itappertains to make and use the same.

This invention relates to improvements in spark plugs for internalcombustion engines and the l1ke,-one object of the invention being to soconstruct a spark plug that the arc shall be intensified and its areaincreased.

A further object is to provide a spark plug in which the intensity andarea of the arc shall be enhanced magnetically.

A further object is to so construct a spark plug that it shall be simpleand eflicient and so that the terminals shall remain practically free ofcarbon deposit.

With these and other objects in view, the invention consists in certainnovel features of construction and combinations of parts ashereinafte'r'set forth and pointed out in the claims.

In the accompanying drawings, Figure 1 is a view in elevation of a sparkplug embodying my invention. Fig. 2 is a sectional view of the same, andFigs. 3 and 4.- are sectional views showing modifications.

1 represents the shell or casing of the plug and consists of magneticmaterial, suc as iron. This iron shell is threaded externally to screwinto the wall of the combustion chamber of the engine and at its loweror inner end, it is provided with an inwardly projecting annular flange2 which sustains a cap 3. This cap (which is preferably made of Germansilver and forms one of the sparking terminals of the plug) is slottedto form a plurality of curved fingers and is held in place of insulatingmaterial. The block or disk 4 is perforated for the passage of an ironconducting rod 5 provided at its lower end with a tip 6 (which may bemade of German silver) forming the other sparking terminal.

The conducting rod 5 also constitutes the core of an electro-magnet, thecoil 7 of which is located within the shell 1 and rests at its by meansof a block or disk 4 lower end against the insulating block or disk 4.One end of the coil 7 is electrically Patented Oct. 30, 1917. a

connected with the rod or core 5 so as. to be in the electrical circuitof the plug, and the other end of said coil is mounted in a recessedblock 8 of insulating material disposed over the rod or core 5. A sleeve9 (preferably of porcelain) enters the upper portion of the shell'l andis formed with an annular shoulder 10 to be engaged by a nut 11 screwedinto the shell 1 and encircling said sleeve. A conducting rod 12 passesthrough the sleeve 9 and is formed at its inner end with a head orupset'portion 13 which enters a recess 14 in the inner end of the sleeveand also makes electrical contact with the exposed endof the Wire ofcoil 7 which rests on the insulating block 8.

The conducting rod 12 projects above or beyond'the porcelain sleeve 9and is threaded for the reception of a clamping nut 15 which bearsagainst .the free end of said sleeve and a nut 16 is also mounted on therod 12 so as to cooperate therewith and with the nut 15 to form abinding post for one of the circuit terminals.

With the construction and arrangement of parts above described, a simpleand efficient spark plug is formed, and the sparking terminals are soconstructed and disposed as to avoid the accumulation of carbon depositthereon.

It will alsobe observed that when the sparking circuit is closed, amagnetic field will be established as indicated in Fig. 1, the magneticlines of force passing through the spark gap andacting to intensify thearc constituting the spark and also to extend the area of said are, thusenhancing the efliciency of the same.

Instead of employing an electro-magnet aS shown in Fig. 2, I may employapermanent magnet 17 inserted within the shell of the plug andelectrically insulated from the conducting rods 12-18 as shown in Fig.3, or I may employ a magnetized plug body 19', such as shown in Fig. 4,'with the conducting rod 20 electrically insulated therefrom as'shown at21.

Various other changes might be made in the details of construction of minvention without departing from the spirit thereof or limiting itsscope and hence I do not wish to restrict myself to'the precise detailsherein set forth.

Having fully described my invention What I claim as new and desire tosecure by Letters-Patent, is:

1. The combination with the sparking terminals of a spark plug, of meansfor setting up a magnetic field past the are formed between saidterminals.

2. A spark plug provided with means for setting up magnetic lines offorce past the spark gap of said plug.

3. A spark plug having electrically separated sparking terminals, saidplug em bodying magnetic means disposed to establish a magnetic fieldhaving its lines of force passing through the gap between said sparkingterminals.

4. A spark plug embodying in its structure, a magnet having one of itspoles disposed in such proximity to the sparking terminals of the plugas to cause magnetic lines of force to be cast against the arc formed atsaid sparking terminals.

5. 'In a spark plug, the combination of a shell, a sparking terminalcarried thereby, an electro-magnet within said shell, the core of saidmagnet provided with the other sparking terminal and included in circuitwith said coil, and means for including said coil and core in anelectric circuit and said core and shell being so correlated that magnetic lines of force will pass throu h the spark gap duringthe operationof t e de vice.

6. In a spark plug, the combination of an iron shell, a sparkingterminal carried thereby, an electro-magnet within said shell and havingone terminal of its coil connected with the core thereof, a sparkingterminal carried by the core of said magnet, a sleeve of insulatingmaterial attached to said shell,

an insulating block disposed between said sleeve and magnet andsupporting an exposed terminal of the .coil of said magnet, and aconducting rod passing through said sleeve and in electrical contactwith the exposed terminal'of said coil, said core and shell being socorrelated that magnetic lines of forcewill be caused to pass throughthe spark gap during the operation of the device.

7. In a spark plug, the combination of a shell, a sparking terminalcarried thereby, a conducting rod carrying a sparking terminal, a sleeveof insulating material entering one end of the shell, a nut holding saidsleeve in place, a conducting rod passing through sald sleeve and havinga head at its under end electrically connected with the first mentionedconducting rod, a nut on the last-mentioned conducting rod and engagingsaid insulating sleeve, and a wire clamping nut on said rod.

8. In a spark plug, the combination with a shell, of a cap at the lowerend thereof having a plurality of fingers constituting one side of thespark plug, an insulating block holding said cap in place, a central rodprovided with a tip forming theother side of the spark gap, and meansfor effecting electrical connection of said rod in'a sparking circuit.

In testimony whereof, I have signed this specification in the presenceof two subscribing witnesses.

ETHAN I. DODDS.

Witnesses:

EDWIN S. RYCE, F. H. ALLISON.

